It's a fairly comprehensive write-up. I'm mostly familiar with the Hatha Yoga context of mudras.
There's also a few dozen books on the topic. I'd stick to the older more original texts if you want a real understanding, and stay away from the more modern new age fluffy bunny "crystal mudras" nonsense.
What are your (you guys) opinions on Session (https://getsession.org/), the Signal clone that uses Tor, and no phone numbers? Any significant downsides? Anybody know the team there and can speak on their trustworthiness, longer term intentions etc? What about the code they've added? Anybody review that? At a quick glance it looks like a decent but less user friendly alternative (no phone numbers - good for privacy, bad for grandma's to be able to adopt it easily). Thanks.